Breast cancer is the most frequent neoplasm and the leading cause of cancer mortality in women worldwide. According to estimates, approximately 41,000 women in the United States and 130,000 women in the European Union die from breast cancer yearly.
Detection of breast cancer at the earliest stages results in a much greater favorable outcome, with 10-year disease-free survival rate as high as 98% in patients in which the tumor stage is pT1a,bN0M0 (measuring 1 cm or less, with disease-free axillary lymph nodes and no distant metastasis). Needless to say, early detection is of paramount importance in reducing mortality from this major public health burden.
Current breast cancer detection methods are based on physical examination and imaging (for example, mammography, ultrasound, and MRI). These methods can produce a substantial percentage of false positive and false negative results especially in women with dense parenchymal breast tissue. Consequently, screening results in a number of negative biopsy results yielding a high percentage of false positives. There is also a demonstrated lack of sensitivity in detecting cancerous lesions in younger women yielding a significant percentage of false negatives. Accordingly, a clear need exists for added modalities of screening for breast cancer.
In the last decade, biomarker discoveries for breast cancer detection have focused on blood/or tissue, using proteomic, transcriptomic, and genomic approaches. In comparison to prognostic biomarkers, the development of detection biomarkers has been limited, mainly due to a lack of sensitivity and specificity for this clinical context. Most importantly, the use of tissue biomarkers for early detection will be limited to patients at very high risk because they rely on invasive procedures.
As such, a need exists for methods useful for detecting breast cancer, and in particular biomarkers that can detect early stages of the disease and are largely non-invasive.